Facebook lets photos go fullscreen, but only on Chrome, Firefox

Facebook today updated its Photo services with two new features: high-resolution photos and full screen viewing. Unfortunately, the latter only works on Google Chrome and Mozilla Firefox.

Facebook today announced a few enhancements to its photo viewer, including high-resolution photos and fullscreen viewing. The photo viewer now automatically displays photos in the highest resolution possible (this can be up to four times bigger than before) and you can also expand the photo viewer to take up your entire computer screen.

The fullscreen feature is only available on the latest version of Chrome and Firefox. To use it, click the arrows at the top-right corner of a photo to expand it. Facebook confirmed with me that only these two browsers are being supported, but wouldn't elaborate as to why. I've also asked when other browsers will be supported, and I will update you if I hear back. Update: I was merely told that Facebook is planning to support other browsers in the future.

As for the larger and better quality images, there are some more technical details behind this update. The Internet standard color profile is called standard Red Green Blue (sRGB). Every photo on Facebook and most of the Internet uses the sRGB profile, but since most browsers don't assume each image is in sRGB, websites often have to redefine sRGB in every single image. Facebook wasn't doing that yet, but when it tried, the company realized that the definition was too big (~3KB). Because of all the images on the site (especially the small thumbnails), such a large definition could slow down page loading by up to 30 percent.

To make the sRGB profile smaller, Facebook first cut out all the redundant information (only 2060 bytes were actual critical information, and a lot of that was being repeated for all three RGB color lines). Next, the company noticed that the "tone response curve" was responsible for a lot of the 2060 bytes. A sampling of 1024 points along the curve was being used, but JPEG only requires 256, and it turns out that only 26 points are actually necessary. Once that number was cut down, the sRGB profile became very manageable. You can read the full story yourself over at Facebook Engineering.

250 million photos are uploaded to Facebook every day. While I'm sure the company would love to display all of them in their original format, it's just not possible. That being said, as browsers and Internet connections continue to improve, you can expect the same for the quality of images on Facebook.

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